Well-completion apparatus



United States Patent Primary Examiner-David H. Brown Attorneys-Ernest R. Archambeau, Jr.. William J. Beard,

David L. Moseley, Edward M. Roney, William R. Sherman and Stewart F. Moore ABSTRACT: The particular embodiment described herein as illustrative of the invention is directed to new and improved well bore apparatus for more reliably performing selected well-completion operations. To accomplish this, the disclosed well bore apparatus includes an elongated support having first and second longitudinally spaced forward faces that are uniquely arranged to normally position the second forward face in advance of the first forward face. Selectively operable anchoring means are adapted for extension from the rear of the first face for urging this forward face against an adjacent well bore wall and, by virtue of the unique arrangement disclosed herein,-upon constraint of the adjacent portion of the support progressively flexing the support member rearwardly to urge the second forward face forwardly with a force corresponding to the degree of rearward deflection of the second forward face. In this manner, selectively operable wellcompletion means arranged for operation between these forward faces will be reliably positioned in relation to the adjacent well bore wall.

PATENTEU DEE29 mm SHEET 1 BF 2 Harold J. Urbanosk y /N VENTOR A T TORNE Y .PATENTED DECZS 19m sum 2 OF 2 Harold J. Urbanosk y A T TORNE Y 1 WELL-COMPLETION APPARATUS There are, of course, a large variety of well-completion tools introduced each year which include one ormore laterally directed testing, sampling or logging devices that must be accurately positioned in relation to selected wall surfaces in a well bore. Typical of such tools are those shown in U.S. Pat. No. 3,173,500 which have been recently proposed for obtaining single formation samples of a substantial length. In these tools, a pair of rotatable, outwardly converging cutting wheels are arranged to be extended laterally through an elongated opening in the tool housing for cutting their way into an adjacent formation. Then, as the cutting wheels are raised in relation to the stationary tool, a single elongated wedge-shaped formation sample is cutout of the borehole wall. This individual sample is caught by the tool and returned to the surface. New and improved repetitively operable tools such as that shown in U.S. Pat. No. 3,430,716 by the present inventor have also been proposed for successively collecting a plurality of such elongated formation samples during a single trip into a borehole. These tools also employ a pair of convergent cutting wheels that are selectively extended laterally and moved longitudinally along an elongated housing opening to cut away one or more formation samples.

Inasmuch as well-completion tools such as these formation sampling tools must operate in relatively small boreholes, the tool housings must necessarily be correspondingly sized. This, of course, dictates that the overall lengthof these tools in turn be quite substantial. For instance, in a typical operational tool of this nature, one or more housings of a combined length in the order of 20 to 30 feet may well be required just to enclose various electrical components within the formation-sampling tool. Moreover, if, for example, formation samples of 4 to feet in length are to be obtained, a sample receiver of at least 5 feet in length is required and that portion of the housing carrying the longitudinally movable cutting wheels must be at least twice that length. Accordingly, it is not at all unusual for fully operational-sampling tools of this nature to have an overall length in the order of 40 to 60 feet.

These severe limitations on the maximum diameter of these operational tools correspondingly determine the longitudinal position of their extendible anchor in relation to the laterally extendible cutting wheels. Since the diameter of typically used cutting wheels as well as an appropriate driver therefor is only slightly smaller than the maximum allowable housing diameter that can be safely used for an operational-sampling tool, it is usually impractical to mount the extendible anchor for the tool in this portion of the housing. Thus, although it perhaps should ideally be positioned behind the cutting wheels, the laterally extendible tool anchor is typically located just above the housing carrying the formation-sampling means.

The substantial length of these sampling tools also creates other significant problems. Those skilled in the art will, of course, appreciate the difficulty in obtaining a satisfactory core sample from a formation wall that is covered with mud cake which can, for example, have a thickness as much as onehalf inch or even more. It will be recognized, therefore, that where the maximum depth of lateral penetration by the cutting wheels is perhaps only in the order of 1 inch or so, unless the forward face of at least that part of the tool housing carrying the cutting wheels is maintained in close proximity to the formation wall, effective samples simply cannot be obtained. Thus, to tightly press the forward face of these fairly lengthy operational sampling tools into a mud-caked formation wall requires a substantial force from the anchor. Moreover, if the borehole is irregular in diameter, should there be one or more outstanding projections either just above or below a formation of interest, it is quite likely that the cutting wheels might not reach the borehole wall even when vide a forward surface of substantial area which may easily 7 become sealingly embedded in a mud cake and held there by the pressure differential between the borehole fluids and connate fluids. Further complications are also presented in designing tools of this nature to offset any rearwardly directed forces imposed on the tool body as the cutting wheels are moved forwardly into a formation wall.

Accordingly, it is an object of the present invention to provide new and improved means for urging selected portions of well tools of substantial length against a well bore wall to accurately position laterally facing devices thereon for cooperative association with the well bore wall.

This and other objects of the present invention are attained by providing well bore apparatus having a rearwardly extendible anchor behind one forward face of the tool and a second, longitudinally displaced face of the tool body normally advanced forwardly of the first face so that rearward extension of the anchor will rigidly constrain the first portion of the tool and maintain the second face against the well bore wall with a substantial reactive force corresponding to the rearward flexure of the intervening length of the body. In this manner, once the tool is anchored, well-completion means arranged between the first and second wall-engaging surfaces are reliably maintained proximate to the well bore wall without a significant surface area of the tool body having to be forced thereagainst.

The novel features of the present invention are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may be best understood by way of the following description of exemplary apparatus employing the principles of the invention as illustrated in the accompanying drawings, in which:

FIG. 1 depicts an exemplary formation-sampling tool including means arranged in accordance-with the present invention, with the tool being anchored in position in a typical borehole for obtaining a formation sample;

FIGS. 2A and 2B are successive views schematically illustrating the tool shown in FIG. 1;

FIGS. 3A, 4A and 5A are schematic views respectively depicting well tools with alternative embodiments of the present invention; and

FIGS. 38, 4B and 5B illustrate the tools respectively depicted in FIGS. 3A, 4A and 5A as they may appear while anchored in a borehole.

Turning now to FIG. 1, a well-completion tool 10 arranged in accordance with the present invention is shown suspended from a cable 11 in a borehole l2 and in position for selective operation of well-completion means such as a pair of converging similar cutting wheels 13 arranged thereon for selectively removing an elongated sample 14 from the exposed face of an earth formation 15 for deposit in a sample receiver 16 on the lower portion of the tool. Suitable circuitry 17 (such as described in a copending application, Ser. No. 649,978 filed Jun. 29, 1967) is provided for locating the well-completion tool 10 at a desired position in the borehole 12 as well as for controlling the tool from the surface by way of electrical conductors in the suspension cable 11.

A pair of pistons 18 are operatively arranged for selectively extending a wall-engaging anchor 19 laterally from the rear of the tool 10 against one side of the borehole 12 to laterally shift the sampling tool in the opposite direction. To actuate the wall-engaging member 19 from the surface, a pump 20 is arranged to selectively pump hydraulic fluid into piston chambers either behind or ahead of the pistons 18 By maintaining an increased hydraulic pressure behind the pistons 18, the

anchor 19 will, therefore, urge the forward face of the housing in the forward wall of the intermediate support or housing 22 of the tool 10, the rotating wheels will cut away a generally wedge-shaped or triangular prismatic sample (as at 14) from the adjacent face of the formation 15.

The receiver 16 in the lowermost portion of the tool includes means for reliably segregating a selected number of formation samples from one another. As described in the Urbanosky patent mentioned above, in one manner of arranging the sample receiver 16, a plurality of upright tubes are sequentially positioned to respectively receive successively collected formation samples as the tool 10 is operated. As an alternate, the sample receiver 16 can also be arranged as shown in the drawings. In the illustrated arrangement, a plurality of upright partitions or transverse dividers (not shown in FIG. 1) are uniquely arranged for selectively isolating the formation samples as they are collected. In either instance, therefore, the tool 10 can be efficiently employed on a single trip in the borehole 12 to recover one or more formation samples that will be individually segregated in the sample receiver 16 in predetermined positions.

Turning now to FIGS. 2A and 28, a somewhat schematic representation is shown of the tool 10 to better appreciate the significance of the present invention. As seen in FIG. 2A, the cutting wheels 13 are dependently carried by a longitudinally movable enclosure 23 having a pair of upright tubular members 24 (only one shown) mounted along its rear wall and slidably disposed about substantially longer rods 25 (only one shown) secured at their upper and lower ends and extending longitudinally adjacent to the rear wall of the tool housing 22. The opposite ends of the tubular members 24 are slidably sealed around these rods 25 and a piston member 26 (only one shown) is fixed at an intermediate position on each of the elongated rods to define separate fluid-tight chambers 27 and 28 within the internal bore of its associated tubular member.

Accordingly, by developing a higher fluid pressure in the upper chambers 27 than that in the lower chambers 28, the enclosure 23 will be moved longitudinally upwardly along the elongated rods 25 in relation to the stationary tool housing 22. Similarly, by imposing a higher pressure in the lower chambers 28, the enclosure 23 will travel longitudinally downwardly along the rods 25. A suitable hydraulic pump 29 is mounted within the enclosure 23 and appropriately arranged to selectively pump hydraulic fluid to the chambers 27 and 28 upon command from the surface as required to shift the enclosure back and forth along the elongated rods 25.

An electric motor 30 in the enclosure 23 is operatively connected by a universal joint to a right-angle gear drive 31 having outwardly diverging shafts for rotatively driving the cutting wheels. A pair of depending arms, as at 32, are pivotally connected at their upper ends to the motor enclosure 23 for supporting the gear drive 31 secured to their lower ends.

To operatively position the cutting wheels 13, outwardly biased guide pins 34 (only one shown) mounted near the lower ends of each of the pivoted arms 32 are slidably disposed in a system of guide grooves 34 (only one system shown) formed in the interior sidewalls of the tool housing 22 on opposite sides of the longitudinal opening 21 therein. These groove systems 34 are arranged so that upward travel of the motor enclosure 23 from its full-line position to its dashedline position will be effective (through the coaction of the guide pins 33 in their respective groove systems) to direct the cutting wheels 13 along an established path. Thus, once the housing enclosure 23 is shifted upwardly a short distance, the groove systems 34 will guide the cutting wheels 13 along the path A-B-C-D for cutting away a prismatic sample, as at 14, with tapered ends from the formation for subsequent deposit in the core receiver 16 therebelow. Then, shortly after the cutting wheels 13 are retracted (position D) the enclosure 23 is halted in its uppermost position as illustrated. When the enclosure 23 is subsequently returned downwardly from its uppermost position, the groove systems 34 are preferably arranged so that the rotating cutting wheels 13 are passed downwardly back through their respective kerfs which they had previously cut into the formation 15 for dislodging the formation sample 14 should it still be in the complementary cavity cut into the formation.

As seen in FIG. 2B, a plurality of upright transverse dividers 35-37 in the sample receiver 16 are selectively positioned. in response to the cyclical upward and downward movemen ts of the motor enclosure 23 for successively segregating the formation samples once they pass through a sample passage 38 communicating the access opening 21 with the upper end of the receiver. To accomplish this, the. dividers 35-37 are initially positioned along the rear wall ofthe housing 22 and releasably retained in this position by a somewhat U-shaped latch 39 arranged for controlled vertical travel relative thereto. Thus, when the first formation sample is cut away by the cutting wheels 13, it will pass through the housing opening 21 and passage 38 and come to rest on the forward face of the first divider 35.

As described in more detail in a copending application Ser.

No. 765,383 filed Oct. 7, 1968) by the present inventor, to successively release the dividers in response to subsequent cyclical operations of the tool 10, the upper ends of the dividers 35-37 are reduced in width, as at 40-,"42, at progressively higher points. By progressively moving the U- shaped latch 39 upwardly to each of these shoulders 40-42 in turn, a number of U-shaped springs, as at 43, respectively biasing the dividers 3537 will sequentially shift the reduced upper ends of the dividers forwardly between the inwardly turned opposed fingers 44 of the latch. Thus, although upward travel of the latch 39 will ultimately release all of the dividers 3537, only one divider will be released at a time and the other dividers will be retained against the rear wall of the housing 22 until the latchhas been shifted further upwardly by subsequent operations ofth'e tool 10.

To control the longitudinal travel of the latch 39, a vertical spindle shaft 45 is journaled between longitudinally spaced bearings 46 and 47 mounted on the rear wall of the housing 22 just below the latch. A somewhat resilient cam follower 48 dependently secured to the latch 39 is extended downwardly alongside the spindle 45 and cooperatively guided by a system of zigzagged or alternating cam grooves 49 formed around the rotatable spindle and providing progressively higher cam stops (not shown) respectively spaced to correspond with the progressively higher shoulders 40-42 on the dividers 35-37.

As fully described in the last-mentioned copending application, the alternating cam-guiding system 49 includes a plurality of circumferentially spaced longitudinal grooves having their upper ends located at progressively higher positions on the vertical spindle 45 to provide the above-mentioned cam stops and a plurality of downwardly inclined grooves respectively interconnecting the upper end of each longitudinal groove to the lower end of the next adjacent and higher longitudinal groove. In this manner, an alternating but continuous path is defined around the spindle 47 that begins at the lowermost longitudinal groove and zigzags upwardly on around the spindle to the uppermost longitudinal groove and is completed by the final inclined groove which extends downwardly from the upper end of the uppermost longitudinal groove back to the lower end of the lowermost longitudinal groove. Shoulders are appropriately located across the exit of each of the grooves on the spindle 45 to assure that the cam follower 48 will progressively move around the spindle along the zigzagged path 49.

It will be appreciated, therefore, that successive reciprocating movements of the latch 39 will progressively shift its depending cam follower 48 on through the spindle grooves 49 to progressively halt the latch at a successively higher elevation as determined by the upper ends of the longitudinal spindle grooves. Accordingly, by spacing the divider shoulders 40- 42 to correspond with the vertical spacing of the cam stops on the spindle 45, successive reciprocations of the latch 39 will sequentially release the dividers 35-37 as the latch is progressively raised above the shoulders.

To selectively reciprocate the latch 39 in response to the cyclical operations of the sample-collecting means 13, an upright-actuating member 50 is secured tothe latch and slidably guided for vertical reciprocation along the rear wall of the housing 22. An actuator rod 51 depending from the motor enclosure 23 (FIG. 2A) is provided with an enlarged lower end 52 that is adapted to be selectively received by a plurality of upwardly extending yieldable collet fingers 53 on the upper end of the actuating member 50.

Accordingly, upon initial upward travel of the enclosure 23, the actuator rod 51 will pull the depending cam follower 48 (as well as the actuating member 50 and latch 39) a short distance upwardly until it is halted by contacting the top of the longitudinal spindle groove it is then in'. Once these members are halted, the continued upward travel of the enclosure 23 will retract the enlarged rod head 52 from-the yieldable collet fingers 53 and friction will retain the latch 39 in its elevated position. Then, when the motor enclosure 23 is subsequently returned downwardly the enlarged rod head 5 2 will again contact the collet 53 and push the actuating member 50 downwardly until it is halted when the cam follower 48 reaches the bottom of the next adjacent longitudinal spindle groove. Once the actuating member 50 is halted, continued downward travel of the motor enclosure 23 toward its final position will push the enlarged rod head 52 back into engagement with the collet fingers.

It will be appreciated, therefore, that the unique arrangement of the sampling tool will permit multiple formation samples to be successively collected and reliably segregated in the receiver 16 for subsequent recovery and examination at the surface. As previously mentioned,-however, there are still the conflicting risks that either the forward face of the tool 10 may become differentially stuck in the borehole 12 or else that theforward face of the tool will not be maintained sufficiently close to the borehole wall to secure an adequate formation sample.

Accordingly, to best illustrate the invention, FIGS. 3A, 4A and 5A depict somewhat schematic representations of wellcompletion tools respectively provided with exemplary embodiments of flexure-inducing means arranged in accordance with the principles of the present invention; with FIGS. 38, 4B and 5B correspondingly showing these respective tools anchoringly engaged in a typical well bore. it will be understood, however, that although these various embodiments of the flexure-inducing means of the present invention are shown with the formation-sampling tool 10 as described above, the present invention also has utility for other types of well-completion tools. 7

Turning now to FIG. 3A, a somewhat exaggerated illustration is shown of the intermediate portion of the formationsampling tool 10 to describe one manner in which the present invention can be accomplished. As seen in this drawing, the anchor 19 is arranged in the upper portion of the intermediate tool housing 22 and, as previously described, adapted for selective lateral extension from the rear of the housing. Similarly, as already described, the formation-cutting wheels 13 are operatively mounted in the lower portion of the housing 22 below the anchor 19 for selective operation on the front of the tool housing.

In accordance with the invention, the illustrated portions of the tool housing 22 are uniquely arranged in a noncollinear the laterally offset, longitudinally spaced forward surfaces 54 and 55 engage the adjacent wall of the borehole 12, the outwardly acting anchor forces will be effective to rigidly constrain the upper portion of the housing 22 which, in turn, compels rearward flexure of the intervening portion of the housing lying between these surfaces. As a result of the rearward deflection (as at 57) of the lower surface 54 in relation to the upper surface 55, the flexure of the housing 22 will develop a forwardly directed force (as at 58) urging the lower surface against the borehole wall. Similarly, the anchor 19 will be urged against one side of the borehole wall with a force (as at 59) and simultaneously urge the upper surface 55 forwardly with a corresponding equal, but oppositely directed force (as at 60).

For the theoretical standpoint, therefore, it will be recognized that the intervening portion of the housing 22 constitutes a cantilevered beam that is rigidly constrained at its upper end and rearwardly deflected at its free lower end. Thus, the forwardly directed force 58 will be directly related to the distance 57 that the lower surface 54 is deflected to the rear, with the force 58 being independent of the magnitude of relationship so as to normally incline and position a selected forward surface 54 of the housing below the cutting wheels 13 slightly in advance of the forward housing surface 55 that is opposite the wall-engaging member 19 above the cutting wheels. The upper and lower illustrated portions of the housing 22 are either arranged as a single integral member or, if preferred, are tandemly coupled (as at 56) to one another in an appropriate manner to provide a substantially rigid interconnection therebetween.

Accordingly, it will be appreciated by comparison of the angularly distorted views of the tool 10 shown in FIGS. 3A and 38 that upon extension of the wall-engaging anchor 19, once the oppositely directed anchoring forces 59 and 60. Accordingly, the magnitude of the forwardly acting force 58 will be related only to the longitudinal spacing between the surfaces 54 and 55, the initial forward displacement of the forward surface 54, and the beam characteristics of the intervening portion of the housing 22. Thus, although the oppositely directed anchoringforces 59 and 60 may be'in the order of several thousand pounds, the forwardly directed force 58 induced by flexure of the housing 22 may be only a few hundred pounds. This lesser force 58-will, however, be more than sufficient to counter any lateral reaction against the cutting wheels 13 as they advance into the formation 15.

It will be appreciated from viewing FIG. 38, that by merely canting the two adjacent portions of the tool housing 22 to provide the desired relative inclination between the spaced forward surfaces 54 and 55, in some situations the full advantages of this unique arrangement of the present invention will not always be obtained. For instance, should there be an outstanding projection from the wall of the borehole 12 between the longitudinally spaced surfaces 54 and 55, the amount of rearward deflection 57 may well be reduced with a corresponding decrease, and perhaps a dispersion, of the effective forwardly acting force 58. Moreover, there is also a possibility that the forward face of the intervening portion of the housing 22 between the surfaces 54 and 5 5 will be sealingly imbedded into a borehole mud cake with the attendant risk that the tool 10 may become differentially stuck.

Accordingly, to provide a slight clearance between the borehole wall and the forward face of the housing 22 between the longitudinally spaced wall-engaging surfaces of the present invention, the tool 10 may be arranged as illustrated in FIGS. 4A and 4B. Thus, instead of simply canting the housing, as best seen in FIG. 4A the upper forward inclined face 55 is provided by a tapered wall-engaging member 61 mounted on the tool housing 22 diametrically opposite from the anchor 19. By tapering this wall-engaging member 61 in the manner shown with exaggerated proportions in FIG. 4A, rearward flexure of the intervening portion of the housing 22 will be attained as previously described upon extension of the anchor 19.

, Accordingly, as depicted in FIG. 4B, the tool housing 22 will be similarly bowed rearwardly to develop the unique holding force 58 acting forwardly from the deflected lower surface 54. Of particular significance, however, it will be noted that in FIG. 4B, the projection of the tapered shoe 61 will provide greater clearance between the forward face of the intervening portion of the housing 22 and the borehole wall than is possible with the arrangement of the present invention shown in FIG. 3A. Accordingly, a measure of protection against differential sticking is provided by employing the wedge-shaped wall-engaging member 55 to define the cooperative relative inclinations of the spaced forward faces 54 and 55.

lt will, of course, be appreciated that with the upper and lower portions of the housing 22 being collinear as shown in FIG. 4A, the magnitude of the rearward deflection that can be induced at the lower surface 54 will be solely determined by the dimensions of the tapered shoe 6]. Moreover, due to practical limitations in the geometry of the tool 10 and member 61, there will be only a slight degree of permissible variation that can be provided by varying the dimensions of the tapered shoe.

Accordingly, in the preferred manner of practicing the present invention as shown in FIG. A, the upper and lower portions of the housing 22 are canted in relation to one another in addition to employing the wedge-shaped shoe 61 to achieve a desired rearward deflection at the lower surface as well as still provide a slight clearance between the borehole wall and the intervening portion of the housing between the spaced forward surfaces 54 and 55. Thus, as best illustrated in exaggerated form in FIG. 5B and more accurately in FIG. 1, in response to the rearward extension of the anchor 19 to rigidly constrain the tool housing 22 adjacent to the upper surface 55,

the lower forward surface 54 will be deflected rearwardly from its normal laterally advanced position. As previously explained, deflection of the lower surface 54 will flex the intervening portion of the housing 22 rearwardly to develop the forwardly-directed lateral force for urging the forward wallengaging surface firmly against the adjacent wall surface of the borehole 12.

It should be noted in passing that the above described rearward flexural movements of the tool housing 22 are not influenced by those portions of the tool respectively below and above the two cooperative wall-engaging surfaces 54 and 55. The upper portion of the tool above the anchor 18 is obviously totally incapable of affecting the cooperative flexure of the tool housing 22 once the anchor is extended. To prevent the sample receiver 16 from influencing the flexure of the housing 22, it may either be nonrigidly coupled to the housing or else the upper end of the receiver may be slightly recessed. In either case, even though the sample receiver 16 might engage the wall of the borehole 12, flexing of the housing 22 will still be determined by the longitudinal spacing between the two wall-engaging surfaces 54 and 55.

It will be appreciated, therefore, that once the tool 10 is set as illustrated in FIG. 1, the intervening portion of the housing 22 between the forward load-bearing points at 54 and 55 will be maintained in close proximity to the exposed wall of the formation from which a sample 14 is to be obtained. Moreover, by virtue of the forwardly acting forces respectively developed at the spaced, relatively inclined surfaces 54 and 55, the housing 22 will be reliably maintained in a desired position in relation to the wall of the borehole 12 to insure maximum lateral penetration of the cutting wheels 13 as they are progressively advanced into and along the formation 15. In this manner, formation samples (as at 14) with maximum lateral dimensions will be obtained at a minimum risk of having the tool 10 differentially stuck in the borehole 12.

Accordingly, although changes and modifications may be made in the disclosed embodiments without departing from the principles of the present invention as defined in the appended claims, it will be appreciated that the present invention provides new and improved means for reliably positioning laterally directed devices on well bore apparatus. By arranging longitudinally spaced wall-engaging surfaces on the tool body that are above and below the device and inclined toward a common intersection therebetween, upon rigid anchoring of one of these surfaces the other surface being in advance thereof will reversely flex the intervening portion of the tool body to develop an outwardly directed force at this other surface to insure that the device between the surfaces is accurately positioned adjacent to the well bore wall.

lclaim:

1. Well bore apparatus adapted for suspension in a well bore and comprising: an elongated support having an intermediate portion with a selected side thereof lying between longituforwardly to bring said selected side adjacent-to the opposite wall of that well bore and rigidly constrain said one spaced portion in that well bore; and means responsive only to engagement of said spaced portions with-that opposite well bore wall for flexing said support to correspondingly urge the other of said spaced portions forwardly thereagainst to position said selected side adjacent thereto.

2. The well bore apparatus of claim 1 wherein said cooperative means include formation-sampling means adapted for obtaining a sample from earth formations adjacent to that opposite well bore wall.

3. The well bore apparatus ofclaim 1 wherein said cooperative means include wall-cutting means adapted for cutting into that opposite well bore wall.

4. The well bore apparatus of claim 3 further including means on said support and operable from the surface for moving said wall-cutting means longitudinally along said selected I side of said support for producing an elongated cut along that opposite well bore wall.

5. Well bore apparatus adapted for suspension in a well bore and comprising: an elongated supporthaving a selected side thereon; means defining first and second longitudinally spaced wall-engaging surfaces along said selected support side and normally inclined in relation to one another toward a common intersection therebetween to normally laterally displace one of said wall-engaging surfaces ahead of the other of said wall engaging surfaces; anchoring means on said support adapted for rearward extension away from said selected side into engagement with one wall of a well bore to progressively engage said wall-engaging surfaces with the opposite wall of that well bore for operatively bowing said support to bring said wall-engaging surfaces into substantial longitudinal alignment with one another along that opposite well bore wall; and wellcompletion means on said support and adapted for operation between said wall-engaging surfaces once they are substantially aligned.

6. The well bore apparatus of claim 5 wherein said wellcompletion means include means adapted for movement into engagement with the opposite well bore wall upon substantial alignment of said wall-engaging surfaces.

7. The well bore apparatus of claim 5 wherein said anchoring means are adapted for extension along a lateral axis intersecting said first wall-engaging surface from a normal retracted position on the opposite side of said support from said selected side.

8. The well bore apparatus of claim 7 wherein said wellcompletion means include cutting means adapted for cutting into that opposite well bore wall upon substantial alignment of said wall-engaging surfaces.

9. The well bore apparatus of claim 8 further including means on said support selectively operable from the surface for moving said cutting means longitudinally in relation to said selected side for producing a longitudinal cut along that opposite well bore wall.

10. The well bore apparatus of claim 9 wherein said cutting means include a pair of similar cutting wheels rotatively mounted in converging upright planes for producing intersecting longitudinal cuts along that opposite well bore wall.

11. Formation-sampling apparatus adapted for suspension in a borehole traversing earth formations and comprising: an elongated support; anchoring means mounted on one portion of said support and adapted for rearward extension laterally therefrom to advance one side of said support forwardly toward a selected wall ofa borehole upon command from the surface; means defining first and second inclined wall-engaging surfaces on said one side of said support with said first surface being on said one portion and said second surface being on another portion of said support and longitudinally separated from said first surface by an intervening portion of said support, said surfaces being normally inclined in relation to one another so as to be directed toward a mutual intersection therebetween with said second surface being in advance 1 of said first surface whereby, upon extension ,of said anchoring means, said intervening support portion will be flexed rearwardly until said wall-engaging surfaces are aligned with one another along the selected borehole wall to develop a forwardly directed lateral force from said second surface against the selected borehole wall; and formation-sampling means on said support and adaptedifor extension forwardly from said one side of said support.

12. The formation-sampling apparatus of claim 11 wherein said surface-defining means'include a wedge-shaped projection on said one support portion and tapering toward said one side of said intervening support portion and said other support portion.

13. The formation-sampling apparatus of claim 12 wherein said one support portion and said other support portion are noncollinearly aligned in relation to one a'nothe'n l4. Formation-sampling apparatus adapted for suspension in a borehole traversing earth formations and comprising: an elongated rigid support having upper and lower portions thereof longitudinally separated by an intervening support portion; anchoring means on said upper support portion and adapted for extension rearwardly therefrom to advance the forward face of said upper support portionforwardly toward a borehole wall; means responsive to extension of said anchoring means for inducing flexure of said intervening support portion rearwardly to urge the forward face of said lower support portion forwardly against a borehole wall with a force related to the flexure of said intervening support portion; and formation-sampling means on said support and adapted for extension forwardly from the fofwai fice of said intervening support portion to obtain samples of earth formations adjacent thereto once said intervening support portion has been flexed' 15. The formation-sampling apparatus of claim 14 wherein said flexure-inducing means include means for normally maintaining said upper support portion in noncollinear alignment with said intervening and said lower support portions so as to normally position said lower face in advance of said upper face so that as said anchoring means urge said upper face into contact with a borehole wall, said lower forward face will also contact that borehole wall and be deflected rearwardly into longitudinal alignment with said upper forward face and produce said flexure of said intervening support portion.

16. The formation-sampling apparatus of claim 14 wherein said flexure-inducing means include a wedge-shaped member projecting from said upper forward face and having a forward wall-engaging surface inclined downwardly and rearwardly toward intersection with said intervening forward face so that as said anchoring means urge said wall-engaging surface into contact with a borehole wall, said lower forward face will also contact that borehole wall and be deflected rearwardly into longitudinal alignment with said forward wall-engaging surface and produce said flexure of said intervening support portion.

17. The formation-sampling apparatus-of claim 16 wherein said flexure-inducing means further include means for normally maintaining said upper support portion in noncollinear alignment with said intervening and said lower support portions so as to normally position said lower face in advance of said wall-engaging surface to produce further rearward flexure of said intervening support portion upon extension of said anchoring means. 

